Magistrate Sue O'Connor found Lumsden failed to put his police car in park and when it rolled forward, he hit the accelerator instead of the brake to stop the vehicle, running over Benjamin Wormwell, 17.

"The police car rolled over Mr Wormwell and his bike at sufficient speed to allow its momentum to continue after the collision, and the car mounted the kerb and rolled onto the footpath," Magistrate O'Connor said.

"As an experienced police officer with vast experience with such traffic offences, his failure to engage park suggests panic or a lack of care due to rushing to detain motorbike riders he assumed had committed an offence."

Magistrate O'Connor rejected Lumsden's argument at trial that the incident did not amount to an act of driving because there was no element of control.

"He was in control of the police car when he started to leave it without putting the gear shifter in park," she said.

"He was in control of the vehicle when he tried to depress the footbrake but hit the accelerator.

"I reject that his actions were involuntary, and I reject that his mistakes ormisjudgements should be seen as accidental and not careless."

Victim doubts if officer remorseful

Lumsden's defence lawyer told the court his client was genuinely remorseful and the accident had a "sobering and dramatic effect" on him.

But outside court, Mr Wormwell said he did not believe Lumsden was contrite.

"He has had many chances to say sorry to me — even today he didn't say sorry," he said.

"I missed out on the rest of my schooling, my education and jobs and … now because I'm a liability, it's a lot harder than it was before the accident," he said.

"Obviously the six months and fines aren't going to reflect what I went through, but at least he didn't get off scot-free."

In handing down the sentence, Magistrate O'Connor said a six-month loss of licence would have a "marked impact" on Lumsden's policing career.

"Up and until now you have been hardworking, diligent and respected and have had a good police career, which has now been marred by what seems to have been a temporary misjudgement of a circumstance," she said.

"You have made a very bad misjudgement of the situation but it's not suggested that that's in your character."

Car 'went over me, spat the bike out'

Mr Wormwell suffered multiple broken bones and had screws inserted in his pelvis, as well as a rod in his femur.

He had to spend 10 weeks in hospital.

The apprentice mechanic previously told the court he had been visiting a friend when the incident occurred.

He said the police car "went over me, spat the bike out and dragged me between the footpath and the kerb".

"It was an aggressive acceleration — it was quite fast and the engine revved quite a lot," he said.